The long term objective of the proposed work is to modify carbon cartridges for efficient removal of blood toxins. Carbon adsorption is employed for the removal of strongly adsorbable toxins in some artificial kidney systems as well as in most artificial liver configurations. In the regenerative Artificial Kidney application, a carbon bed with about 250 g of activated carbon is used to adsorb the strongly absorbable species which accumulate between dialysis sessions. The specific aims of the Phase I work are to demonstrate the feasibility of reliable, modification of a carbon bed. The model species that we will investigate will be creatinine, uric acid and Vitamin B12 and urea. With the successful completion of these modification methods we will perform a preliminary conceptual design of a regeneration system and a procedure for two applications: (a) carbon beds used to adsorb uric acid, creatinine middle molecules, etc., in regenerative closed loop artificial kidneys, such as the Electrochemically Regenerative Artificial Kidney being developed be Giner, Inc. and the Redy System and (b) an Artificial Kidney based on the adsorption of urea on carbon.